A plug-in connector is described in European Patent Application No. 713 005. The plug-in connector is arranged in an electrically conductive manner between a high-voltage output of an ignition coil and the terminal section of a spark plug. The plug-in connector is mounted rigidly on the ignition coil and in a longitudinally displaceable manner, via a plug-and-socket connection, on the spark plug. While the spark plug is screwed into a pocket of a cylinder head of the internal combustion engine, the ignition coil rests on a cover surface of the cylinder head at the free end of the pocket and is rigidly secured here as is the spark plug.
When the plug-in connector is mounted, the dimensional tolerances of the spark plug, pit, and ignition coil result in length tolerances of up to 5 mm. Since the plug-in connector is rigidly connected to the ignition coil, the tolerance is compensated at the spark plug. This may result in an undesirable overlapping of the plug-in connector over the terminal section of the spark plug.
As a result of such a partial high-voltage overlapping of the plug-in connector over the connection section of the spark plug, undesirable high-voltage sparkover may occur at the terminal section of the spark plug.
The plug-in connector according to the present invention, in particular for ignition systems of motor vehicles, has the advantage over the related art that the above-mentioned shortcoming is eliminated. For this purpose, the plug-in connector is provided with sockets at both of its ends. A first socket is latched on a stud of the ignition coil so it can be pressed over, forming a pre-assembly unit between the ignition coil and the plug-in connector.
When the pre-assembly unit is mounted on a spark plug, a protective jacket of the plug-in connector slides onto an insulator of the spark plug up to a predefined end position. This slide path is limited by a stop, which is incorporated in a second socket of the plug-in connector and on which a terminal stud of the spark plug comes to rest. In addition, the second socket latches onto the terminal stud.
If the set-up motion continued, the first socket may unlatch and move to a press-over section of the coil stud to compensate the assembly tolerances.
This ensures that the protective jacket always adequately covers the insulator of the spark plug regardless of the assembly tolerances, and tolerance compensation can take place at the connection between the plug-in connector and the ignition coil.